Preserving jar and top grinding device



Dec. 17, 1946. I o. FLECK 2,412,572

PRESERVING JAR AND TOP GRINDING DEVICE Filed May 20, 1944 -/5 INVENTOR.

Patented Dec. 17, 1946 UNITED STATES PATENT OFFICE PRES'ERVING J AR AND TOP (BrRINDING DEVICE 4 Claims.

The invention relates to means for grinding to a proper seat the edge portions of receptacles such as preserving jars and particularly jars made of glass, and also toenable finishing of the glass covers for such jars, to the end that a proper surface will be afiorded by which a perfect seal may be effected against jar rubbers and the like.

The-primary object or" the invention is to provide a stationary simple and inexpensive device suitabl for domestic use, by the housewife in the kitchen, to assure safe sealing of jars, with a minimum of difficulty and without requiring expert knowledge or dexterity in the handling of the apparatus.

I am aware of the ommon practice of using abrasive sheets on plain surfaces to effect the finishing of objects of various kinds, but as far as I am aware, no stationary device satisfactory for meeting the needs above stated and hereinafter indicated, is available, it being out of question for the housewife to have an installation of a machine for such use, both on account of the expense, and also because of the fact that only occasional need is felt for such appliances, and the machine would occupy a great deal of valuable space out of proportion to the need.

'It' is ah -important object .of my invention, to provide a stationary device or tool adapted to enable the grinding of the surfaces of the mouth oi jars and the like,

A further important object of the invention is .to. guide the movements of the parts being ground in such manner that uniformity of grinding will be. assured, even through an inexperienced person is operating the device. It is also an. aim to eiiect an economy in the use of abrasive sheets, to the end that liability of tearing of .the same and also waste by failure to use extreme edge portions-will be avoided.

It is also an important aim of the invention topresenta device which will hold the abrasive in a steady mannerwvithout requiring heavy installation or complicated mounting means.

Additional objects, advantages and features of invention reside in the construction, arrangement and combination of parts involved in the embodiment of the invention, as will appear from the following description and accompanying drawing, wherein Figure 1 is a top view of a device embodying my invention, with the work in place.

Figure '2 is a cross sectional View thereof.

Figure3 is a similar view at right angles to Figure 2 on the line 3*3 of Figur 1.

device consisting of a substantially planiform' plate 1 fl, preferably ofmetal, although it may also he produced in plastics, stone and other mate- I rials. The plate is referably square in plan, and oi a thickness preferably somewhat more, or at least-equal to the vertical dimensions of aglass jar top A I, from its grin ing f ce to the crown portion [2, as shown in Figure 5. It will behoted that the crown portion l2 of the jar top terminates at ashoulder l3, below which is a horizontal flange portion M, the lower side of which is to be ground to fit the corresponding surface offithe mouth of the jar, as is well understood in preserving jars and the like. The plate ill is formed with a perfectly planiform upper ortop surface l5, and on its lower side is provided with a number of rubber-faced knobs lfi'adapted to be set on table tops and the like, tohold the device with a minimum tendency to slip on the table top. The plate is formed with a central large opening [1, the edge portion of whichis rabbeted at the lower side of the plate, as at l8, thus forming-a flange [9 which forms a continuation of thetop surface of the plate along the opening l7, and the surface is preferably bevelled as indicated at l8.

An annular ring Eligis provided, consisting of a-moderately thin annular wall having diametrically opposite anchor ears 2| adjacent the upper edge of the ring, the ring having sufficient depth to afford rigidity when clamped upon the plate It, as will be described, the lower edge portion of the ring .23 being smoothly finished in a plane normal to. the axis of the ring. The plate Ill is tapped and threaded to receive bolts 22 engaged through the, ears 2| loosely, so that the ring 20 maybe secured in clamping engagement with the abrasive sheet laid upon the plate [6, with thering 29in concentric relation to the opening H. The diameter of the opening I! is somewhat less than one-half the diameter of the ring 20, and in no case should it beso large that the distance from any point on the inner face of the ring to a diametrically opposite side of the opening H be greater than the diameter'of the jar cap less the width ,ofits under bearing face.

are formed at opposed sides of the ring to I receive grindings and other foreign matter removed from the jar and abrasive sheet. The bolts are then tightened so as to hold the sheet firmly in place upon the plate 10. The jar H to be ground is emplaced within the ring, substantially as shown in Figures 1, 2 and 3, and then by grasping the jar it is moved about upon the abrasive sheet with a gyratory motion. If desired, a small quantity of oil may be employed upon the sheet to facilitate grinding. In the gyratory movements of the jar upon the abrasive, small points, hair-like ridges, small grooves and the like are removed under comparatively short manipulations, these faults in the surfaces bein accountable for failure of the seat if they should be present when the jar tops are applied to use upon the jars in the conventional way. Housewives have experienced many failures due to such causes, and in most cases are unaware of the reason for spoilage of canned goods or preserves.

A number of jars having been treated in the manner described, and it is desired to grind the closure caps, the ring and the abrasive sheet is removed from the plate l0, and the latter inverted as in Figures 4 and 5, so that its top may rest upon the table or the like, upon which the article is placed. As shown in Figure 4, a pair of abrasive sheets are employed, arranged in end to end relation, the end portions being formed with semi-circular openings of a diameter the same as the rabbet [8 of the plate. The abrasive sheets are now clamped in position by the ring 20. The closure cap H is then disposed within the rabbet l8 and the openings of the abrasive sheet.

It should be noted that the depth of the rabbet I8 is greater in depth than the vertical dimensions of the shoulder I3 to a substantial extent, so that when the plate In is inverted, as in Figure 5, and the cap ll laid thereon, the flange portion 14 may rest upon the inclined face I8 of the plate it? without the crown portion of the cap engaging against the flange l9.

With the cap in position it is rotated so that the sealing face of the flange will be ground smoothly by engagement with the abrasive sheets.

In Figure 5, I have indicated a tool 23 for rotating the closure cap I I, which comprises a body portion provided with a lower end of a diameter slightly less than the interior of the cap. Upon the lower end of the body an elastic gripping pad 24 is secured. The pad 24 is preferably of rubber or like material, so that a firm grip may be had upon the cap by slight downward pressure upon the pad.

Testing of a closure cap before grinding may be accomplished by removing the abrasive sheets and ring and disposing the cap Within the rabbet 18. If the sealing face of the closure top is true it will lie smoothly within the rabbet without an unbalanced motion. Since the grinding operation produces a change in the appearance of the glass, it can readily be determined what portions require further grinding.

In the event that the abrasive becomes excessively worn, it may be readjusted to bring new 4 abrasive portions into position within the ring 20 by loosening the bolts 22 and drawing the strip of abrasive slidingly under the ring 20 until the new surface is in place. It will be apparent that when one sheet has been used from end to end, it may be drawn inwardly with its end extending across the ring, and a fresh sheet inserted under the ring and its edge advanced into proximity of theedge of the first sheet, substantially as shown in Figure 4, after which the bolts 22 may be again tightened, and grinding proceeded with the same as though an uninterrupted sheet were in place under the ring 20.

In the application of my device to a type of jar wherein the jar has a crown portion for retaining the sealing ring, such as jars known as Corona jars, a slightly different procedure is required. The sealing rim of such jars can be trued up by my device when applied as in Figures 4 and 5 with the device inverted. For treatment of the tops of the jars the device is employed as in Figures 1 to 3.

The sealing edges of such jar tops can be tested for accuracy on the top side or planiform top surface of my device after the clamping ring and abrasive sheets are removed.

This procedure is also applicable to other types of jars. The purpose of the crown portion on certain types of jars is to retain the sealing ring in its proper place. In the drawing are shown only jar tops of this character. It is obvious that in other types of jars and tops, such as above described, wherein the jar has the sealing ring seat and the top none, the device is equally effective.

While I have shown my device with exactitude in a form in which it has been successfully constructed and used, it will, nevertheless, be understood that this is exemplary, and that some modifications in the structure, arrangement of parts, substitution of materials, and equiva1ents, mechanical and otherwise, may be carried out without departing from the spirit of the invention except as may be more specifically indicated by the appended claims, wherein I claim:

1. A combination tool comprising a plate having upper and lower planiform surfaces, an abrasive sheet clamping ring having a planiform lower edge, means to clamp the ring upon the plate, said ring being of a diameter related to the diameter of the work, said plate having a large opening therethrough concentric with the ring, the diameter which, plus the distance between the opening and the ring at one side is less than the diameter of the work, said opening being rabbeted on the under side to a diameter to receive the crown portion of the work free of contact with the plate, for the purposes described.

2. A device for truing the sealing flange of a jar cap comprising a plate having a planiform top surface to serve as a stationary grinding table for support of an abrasive sheet, said plate being reversible to present the bottom side upwardly at times, said bottom side being formed with a central rabbeted portion of a diameter adapted to receive the crown portion of an inverted jar cap so that its outer flange may rest upon an abrasive sheet disposed upon said plate and around said central rabbeted portion.

3. A device of the character described comprising a plate having a planiform top surface to serve as a stationary grinding table for support of an abrasive sheet, said plate being reversible to present the bottom side upwardly, said bottom side being formed with a central rabbeted opening of a diameter adapted to receive the crown portion of an inverted jar can so that its outer flange may rest upon an abrasive sheet disposed upon said plate and around said central opening.

4. A device of the character described comprising a plate having a plam'form top surface to serve as a stationary grinding table for support of an abrasive sheet, said plate being reversible to present the bottom side upwardly, said bottom side being formed with a central rabbeted opening of a diameter adapted to receive the crown portion of an inverted jar cap, said opening having an inclined circumferential surface, whereby the outer flange of a jar cap will rest upon said surface for testing of said cap.

OTTO FLECK. 

